The gunmen riding a motorbike attacked the polio workers in Banaras Orangi Colony of the city.
Assistant Sub-Inspector (ASI) Tabassum was killed in the targeted attack by the militants, police official Gul Nawaz told PTI.
Noone has taken responsibility for the attack but Taliban oppose the polio vaccination as an alleged conspiracy by the West to sterile Muslims.
The immunisation drive against the crippling disease in the area was immediately stopped after the attack, the first incident of violence against polio teams in 2015.
At least 64 polio workers and security personnel escorting the them have been killed in Pakistan by militants.